Carbonaceous materials are commonly used additives and fillers which exhibit interesting structural, mechanical, electrical and electromechanical properties and which have found application in a wide variety of field.
Nevertheless, their application has been found in some cases somewhat limited due to the difficulty in dispersing and compatibilizing such materials with different media, in particular fluorinated phases, due to their inadequate surface hydrophilicity.
From this point of view, much attention has been devoted both on surface modification of said materials by means of surface agents and on covalent functionalization by introduction of fluoroalkyl group on the surface.
Fluoroalkanoyl peroxides have been used in the past as convenient tool for the introduction of the corresponding fluoroalkyl group on carbonaceous materials.
Thus, WO 2006/23921 (DUPONT) 2 Mar. 2006 discloses the functionalization of carbonaceous materials, in particular of fullerenes or curved carbon nanostructures with low molecular weight perfluorodiacyl peroxide of formula [Z—[CF2]d—Oc—[CF2—CFR]b—Oa—[CF2]e—CO—O]2, with a=0 or 1, b=0 to 10, c=0 or 1, d=1 to 10, e=1 to 10. Examples relate to the reaction of bis(perfluoro-2-propoxypropanoyl)peroxide of formula C3F7OCF(CF3)—C(O)—OO—C(O)—CF(CF3)OC3F7 with single-walled carbon nanotubes.
SAWADA, Hideo, et al. Reactions of fluoroalkanoyl peroxides with single-walled carbon nanotubes: application to sidewall modification of single-walled carbon nanotubes with the introduction of fluoroalkyl groups. Polymers for advanced technologies. 2005, vol. 16, p. 764-769. disclose the reaction of perfluorodiacyl peroxides of formula:
wherein Rf=—CF(CF3)OC3F7 or —CF(CF3)OC4F9.
Nevertheless, the processes of the prior art, involving fluorinated perfluoroalkanoyl peroxides, require handling of unstable and potentially explosive low molecular weight fluorinated acyl peroxides.
Moreover the processes of the prior art do not enable accessing functionalization of carbonaceous materials with polymeric fluorooxyalkylene groups. Those groups are of particular interest as they exhibit surface active characteristics which cannot be achieved with low molecular weight counterparts and efficiently modify oil- and water-repellence of the carbonaceous materials surface.
There is thus a current shortfall in the art for a process for the effective functionalization of carbonaceous materials with fluorinated peroxides of increased thermal and storage stability and for functionalized materials thereof having oil- and water-repellence and low-surface energy properties.